PROPHYLACTIC ANTIEMETIC TREATMENT WITH ONDANSETRON IN CHILDREN UNDERGOING TONSILLECTOMY

Background: Children undergoing tonsillectomy are at high risk for pos toperative vomiting. This study was undertaken to compare ondansetron with metoclopramide and droperidol for the prevention of postoperative vomiting after tonsillectomy. Methods: Two hundred fifty-six pediatri c patients, ages 2-12 years, scheduled for outpatient tonsillectomy we re enrolled in a prospectively randomized, double-blinded investigatio n and assigned to one of four treatment regimens: placebo (saline), on dansetron 0.15 mg.kg(-1), metoclopramide 0.5 mg.kg(-1) or droperidol 0 .075 mg.kg(-1). Study drugs were administered intravenously after inha lation induction of anesthesia with halothane, nitrous oxide, and oxyg en. No premedication or neuromuscular blocking agents were used. Trach eal extubation was performed while patients were still deeply anesthet ized. Acetaminophen and meperidine were given for postoperative pain. Patients were observed in the recovery room for a minimum of 4 h befor e discharge. Parents were contacted by telephone 24 h later for follow -up. Results: Ondansetron reduced the incidence of postoperative emesi s from 62% to 27% (relative risk 0.45, 95% confidence interval 0.29 to 0.70, P < 0.001). Metoclopramide and droperidol had no significant ef fect on postoperative vomiting. Conclusions: The intravenous administr ation of ondansetron 0.15 mg.kg(-1) is highly effective in reducing po stoperative emesis in children undergoing tonsillectomy. Metoclopramid e and droperidol at the doses tested are ineffective in this populatio n.